If you are a beginner or not very familiar with suona playing, it is recommended to choose a medium-sized suona. The medium-sized suona has a smaller range and higher pitch, making it easier for beginners to master. Medium-sized suonas are also generally lighter, making them easier to carry and practice with.

On the other hand, if you already have some experience in playing suona and are looking for a more luxurious and grand sound, you can choose a large suona. The large suona has a wider range and deeper timbre, and can produce a louder sound effect.

In summary, choosing a large or medium suona depends on your playing experience and personal musical pursuits.